DUTCH Queen Beatrix announced in a television address tonight that she is to abdicate in favour of her son Crown Prince Willem-Alexander.

The Queen, who turns 75 on Thursday, will hand over to her 45-year-old son on April 30, a public holiday known as Queen's Day. He will become Holland's first King since 1890.

Beatrix, known to most of her subjects simply by the nickname "Bea", has reigned for 33 years. She succeeded her mother, Queen Juliana, who was on the throne for 31 years, in 1980.

In a pre-recorded address to the nation from her Huis ten Bosch palace, Beatrix said: "Responsibility for our country must now lie in the hands of a new generation."

She added: "I am deeply grateful for the great faith you have shown in me in the many years that I could be your Queen."

The country's prime minister, Mark Rutte, a staunch monarchist, paid his respects in a speech that immediately followed Beatrix on all Dutch television channels.

"Since her coronation in 1980 she's applied herself heart and soul for Dutch society," he said.

The new King is a trained pilot and expert in water management who has long been groomed for the throne after slowly discarding his image as a heavy drinking playboy. He has three young daughters with his wife, Princess Maxima, an Argentine investment banker whose father was an agricultre minister in the military junta that ruled Argentina with an iron fist from 1976 to 1983 until it was brought down by defeat to Britain in the Falklands war.

Since her coronation in 1980 she's applied herself heart and soul for Dutch society

Mark Rutte

Dutch monarchs, unlike their British counterparts, do not tend to regard it as a job for life and have a history of retiring to make way for someone younger. Beatrix is already the oldest ever Dutch monarch.

Her abdication comes as the Netherlands prepares to celebrate the 200th anniversary of its monarchy at the end of this year.

Dutch royal watchers believe Beatrix only stayed on this long to see off a challenge to the nation's reputation for tolerance from far-right anti-immigration politician Geert Wilders, who lost badly at the last election in September.

The abdication also comes at a time of personal crisis for Beatrix. A year ago she was struck by personal tragedy when the second of her three sons, Prince Friso, was left in a coma after being engulfed by an avalanche while skiing in Austria. He is not expected to recover.